A vulnerability has been identified in "mod_access_referer", which is an access control module for the Apache web server.

The vulnerability is caused by a NULL pointer dereference bug in the function "is_ip()". This can be exploited by a malicious person to cause a DoS (Denial of Service) on a webserver with the vulnerable module installed by sending a specially crafted HTTP request with a malformed "Referer:" header.

Solution
Don't use this module, since access control based on the "Referer:" header is trivial to circumvent.

Provided and/or discovered by
zillion

Changelog
Further details available to Secunia VIM customers

Deep Links
Links available to Secunia VIM customers